from datetime import datetime, timedelta, timezone
from fastapi import APIRouter, Depends
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func, and_
from app.core.database import get_db
from app.core.deps import get_current_user
from app.models.device import Device
from app.models.energy import EnergyData
from app.models.user import User

router = APIRouter(prefix="/monitoring", tags=["实时监控"])


@router.get("/devices/{device_id}/realtime")
async def device_realtime(device_id: int, db: AsyncSession = Depends(get_db), user: User = Depends(get_current_user)):
    """获取单台设备的最新实时数据"""
    now = datetime.now(timezone.utc)
    five_min_ago = now - timedelta(minutes=5)

    result = await db.execute(
        select(EnergyData).where(
            and_(EnergyData.device_id == device_id, EnergyData.timestamp >= five_min_ago)
        ).order_by(EnergyData.timestamp.desc()).limit(20)
    )
    data_points = result.scalars().all()
    latest = {}
    for d in data_points:
        if d.data_type not in latest:
            latest[d.data_type] = {"value": d.value, "unit": d.unit, "timestamp": str(d.timestamp)}

    device_q = await db.execute(select(Device).where(Device.id == device_id))
    device = device_q.scalar_one_or_none()

    return {
        "device": {
            "id": device.id, "name": device.name, "code": device.code,
            "device_type": device.device_type, "status": device.status,
            "model": device.model, "manufacturer": device.manufacturer,
        } if device else None,
        "data": latest,
    }


@router.get("/energy-flow")
async def energy_flow(db: AsyncSession = Depends(get_db), user: User = Depends(get_current_user)):
    """能流图数据 - 展示能量流向"""
    now = datetime.now(timezone.utc)
    five_min_ago = now - timedelta(minutes=5)

    # 获取各类设备最新功率
    result = await db.execute(
        select(Device.device_type, func.sum(EnergyData.value))
        .join(EnergyData, EnergyData.device_id == Device.id)
        .where(and_(EnergyData.timestamp >= five_min_ago, EnergyData.data_type == "power"))
        .group_by(Device.device_type)
    )
    power_by_type = {row[0]: round(row[1], 2) for row in result.all()}

    pv_power = power_by_type.get("pv_inverter", 0)
    hp_power = power_by_type.get("heat_pump", 0)
    total_load = hp_power + power_by_type.get("meter", 0)
    grid_import = max(0, total_load - pv_power)
    grid_export = max(0, pv_power - total_load)

    return {
        "nodes": [
            {"id": "pv", "name": "光伏发电", "power": pv_power, "unit": "kW"},
            {"id": "grid", "name": "电网", "power": grid_import - grid_export, "unit": "kW"},
            {"id": "heatpump", "name": "热泵系统", "power": hp_power, "unit": "kW"},
            {"id": "building", "name": "建筑负荷", "power": total_load, "unit": "kW"},
        ],
        "links": [
            {"source": "pv", "target": "building", "value": min(pv_power, total_load)},
            {"source": "pv", "target": "grid", "value": grid_export},
            {"source": "grid", "target": "building", "value": grid_import},
            {"source": "grid", "target": "heatpump", "value": hp_power},
        ]
    }